A multilamp photoflash array of the all-glass lamp type and having the same general configuration used herein is disclosed in U.S. Pat. No. 4,133,023, said patent being assigned to the assignee of the present invention. Said flash lamp array also includes a reflector and barrier member of a one-piece construction, preferably of molded white plastic interspersed with titanium dioxide, shaped to provide the reflector cavities for the plurality of flash lamps positioned therein. The barrier portions of said one-piece member prevents sympathetic flashing by which a lamp adjacent to a flashing lamp could be caused to flash due to heat and/or light radiating from the flash lamp. Said one-piece member further includes aperture openings which permit radiant energy passing from the flashing lamps to switch devices below which form part of the circuitry for sequential firing of the flash lamps connected in the circuitry. A serious problem which has been encountered in the operation of this type flash lamp array now occurs when the underlying switch devices undergo overly vigorous conversion from a high electrical resistant state ("off" condition) to a low electrical resistance state ("on" condition) which frequently causes the converted switches to blow off the circuit board member. Removal of switch devices in this manner produces an open circuit condition in the electrical circuitry thereby interrupting the electrical circuit path and preventing further unflashed lamps in the circuitry to be flashed. The problem has also become more severe with employment of higher intensity flash lamps than have previously been employed.
It would be desirable, therefore, to provide a more reliable switch operation in this type flash lamp array without further necessitating a significant departure in the present construction of said array.